Work

Single atom Ru-supported reduced graphene oxide integrated self-assembled monolayer as a nm-scale Cu diffusion barrier

Year: 2025

Type: article

Abstract: In advanced integrated circuits, signal transmission delay arising from interconnect resistance is a main problem hindering the development of electronic devices, while the conventional several-nanometer-thick TaN/Ta barrier with high resistivity causes a surge in interconnect resistance due to the size effect. To address this issue, it is crucial to develop Cu barrier materials. Here, we design an integrated ultra-thin Cu diffusion barrier (~1.4 nm) consisting of single-atom Ru-supported reduced graphene oxide (Ru SA-rGO) and self-assembled monolayer (SAM) derived from (3-aminopropyl)triethoxysilane, which combines the dual functions of liner and barrier. The supporting of Ru requires N-doping as a bridge. Remarkably, the mean time-to-failure of devices with Ru SA-rGO/SAM is approximately 24 times longer than barrier-free devices. Ru atoms can both physically block Cu diffusion by filling rGO vacancies and chemically capture Cu through enhanced adsorption. Our work provides insight into diffusion barrier development in advanced Cu interconnects. This work designs a ~ 1.4 nm structure that integrates the dual functions of barrier and liner for advanced Cu interconnects. It blocks Cu diffusion up to 600 °C and extends the mean time-to-failure by 24 times compared to barrier-free devices.

Source: Nature Communications

DOI: 10.1038/s41467-025-67668-7